142 research outputs found
COAL AND NATURAL GAS TO LIQUID ALKANES BY HYBRID PROCESSING
This report describes a process to convert coal and natural gas to a mixture of liquid hydrocarbons, which is intended to be sold as a feedstock for a refinery. Given that the region has a large amount of coal production and sits atop the Marcellus shale with its expanding natural gas production, as well as the proximity to refineries in Ohio, southwestern Pennsylvania is a natural location for such a venture.
2600 tons per day of coal and 66 million standard cubic feet per day of natural gas are converted to syngas in separate, parallel process trains. The hydrogen rich natural gas syngas is mixed with the hydrogen lean coal syngas to give the desired syngas composition. Fischer-Tropsch chemistry is used to convert syngas with a 2 to 1 H2:CO molar ratio to a distribution of alkanes. The alkanes are separated to give 15,500 barrels per day of liquid product.
The total capital investment of the project was estimated to be 258 million, with an internal rate of return of 11%. The profitability of the project is especially dependent on the price of oil and the total capital investment
Finite element model of an impact on a palmar pad from a snowboard wrist protector
Wrist injuries are the most common types of injury in snowboarding. Protectors can reduce injury risk by limiting wrist hyperextension and attenuating impact forces. There are a range of wrist protector concepts available, but it is unclear if any particular design is more effective. The aim of this study was to develop and validate a finite element model of an impact on the palmar pad from a protector. Pad material from a protector was characterised to obtain stress vs strain data, and determine whether it was rate dependent. Material data was implemented into a finite element model to predict impact behavior at 2.5 J. Four material models were investigated, with an Ogden model paired with a Prony series providing the best agreement to experimental data. Future work will build a model of a complete protector for predicting the protective levels of these products
Thin low-loss dielectric coatings for free-space cloaking
We report stereolithographic polymer-based fabrication and experimental operation of a microwave X-band cloaking
device. The device is a relatively thin (about one wavelength thick) shell of an air-dielectric composite, in which
the dielectric component has negligible loss and dispersion. In a finite band (9.7–10.1 GHz), the shell eliminates the
shadow and strongly suppresses scattering from a conducting cylinder of six-wavelength diameter for TE-polarized
free-space plane waves. The device does not require an immersion liquid or conducting ground planes for its operation.
The dielectric constant of the polymer is low enough (ϵ 2.45) to suggest that this cloaking technique would
be suitable for higher frequency radiation, including visible light.U.S. Army Research Office; Multidisciplinary University Research Initiative (Grant No. W911NF-09-1-0539)
Current oscillations in Vanadium Dioxide: evidence for electrically triggered percolation avalanches
In this work, we experimentally and theoretically explore voltage controlled
oscillations occurring in micro-beams of vanadium dioxide. These oscillations
are a result of the reversible insulator to metal phase transition in vanadium
dioxide. Examining the structure of the observed oscillations in detail, we
propose a modified percolative-avalanche model which allows for
voltage-triggering. This model captures the periodicity and waveshape of the
oscillations as well as several other key features. Importantly, our modeling
shows that while temperature plays a critical role in the vanadium dioxide
phase transition, electrically induced heating cannot act as the primary
instigator of the oscillations in this configuration. This realization leads us
to identify electric field as the most likely candidate for driving the phase
transition
Efficacy of Density in Predicting the Protective Properties of Padded Clothing in Rugby
World Rugby™ permits players to wear padded clothing meeting the requirements of Regulation-12, which limits density, thickness and impact performance. Due to non-uniform geometry, measuring the density of padding can be challenging and provides limited information on mechanical properties. This study investigated how well density could predict the impact performance of rugby padding, whilst reviewing compliance parameters as alternatives. Eleven samples of rugby padding, plus one control material, were tested for compliance, then impacted at energies of 4.9, 9.8 and 14.7 J using the setup as defined in Regulation-12, and finally cut to calculate density. The density and compliance parameters were correlated against peak impact accelerations using a Spearman’s rank test. Density was not significantly correlated with peak acceleration at any energy level, with compliance tests significantly correlated with impact acceleration at only 4.9 J
Use of image based sports case studies for teaching mechanics
Mechanics is a fundamental topic required for both undergraduate and postgraduate students on engineering and technology courses. It can be difficult to motivate and engage students in the theoretical aspects of the topic, especially if they are without a strong mathematical background. There are many sporting examples that can be used to explain some of the basic concepts in mechanics. As many sport interactions are highspeed, visualizing the relation to mechanics can be challenging. From our own research, and that published in the field, we now have access to a range of high quality images that have been generated from high-speed video and photogrammetry work, computational simulations or flow visualizations. Two case studies in which images from ball sport research have been used to explain two key engineering subjects: solid and fluid mechanics. A strategy for future collaboration of academics to share and have access to a range of high quality experimental images was also proposed
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